Sen. M. Teresa Ruiz hugs Joyce Davis after a bill to ban supplemental baby mattresses is passed in the state Senate. (Jonathan Jaffe | For NJ.com)Child safety advocates – and anyone with a baby in their lives – crossed a big hurdle today after a bill to ban the sale of supplemental baby mattresses passed in the New Jersey Senate Monday afternoon.

The vote came down to the wire, with neither side sure of whether the bill would pass. The measure received 21 yes votes, with the rest of the lawmakers not voting.

The bill will return to the Assembly on Thursday to reconcile an amendment, but that’s expected to go through without incident.

Then the bill will have it’s final hurdle when it heads to Gov. Chris Christie’s desk for his signature.

Critics of the mattresses, which are sold separately from playpens and play yards, argued the products pose a suffocation danger to babies because an infant’s head could get stuck in between the mattress and the soft side of a playpen.

Federal warning labels tell parents to only use the mattress or padding that comes with the playpen, but the add-on mattresses have been readily available to consumers.

If the governor signs the bill, the mattresses could no longer be sold in New Jersey.

Joyce Davis, a woman who says her baby died while using a supplemental mattress, started a nonprofit called Keeping Babies Safe (KBS) to promote safe sleep initiatives. She was the driving force behind the bill.

Davis called the vote “an important win.”

“We are ecstatic as this vote is a huge step forward in our effort to rid New Jersey of this terrible product that suffocates babies,” Davis said.

Davis gave thanks to Assemblyman Jamel Holley, who sponsored the Assembly version of the bill, which passed unanimously. She also thanked Sen. M. Teresa Ruiz (D-Essex), the mom of a 9-month-old child, who sponsored the Senate bill.

“I’m glad we were able to convince legislators to do the right thing and support this important piece of legislation,” Ruiz said.

Dream on Me, a Piscataway manufacturer of supplemental mattresses, didn’t immediately respond to requests for comment.

The company hired a lobbying firm to encourage lawmakers to vote no on the measure.

A lobbying letter sent last week told senators the ban was an economic issue. It asked how lawmakers can “justify banning a product that has done no harm and will cost New Jersey 150 jobs?”

Davis and KBS argued it’s a safety issue, not an economic one, and that there is no such thing as a “safe” supplemental mattress because warning labels tell parents not to use any mattress that doesn’t come with a playpen or play yard.

Dream on Me asked the legislature to wait on the Consumer Product Safety Commission (CPSC), which is looking at safety standards for supplemental mattresses.

But safety advocates worried it could be months before any action is taken by the CPSC, so it pushed for the passage of today’s legislation.

CPSC recently tweeted a safety message to parents: “Parents: Only use the mattress that comes with your crib/bassinet/play yard. No supplemental mattresses.”

Davis said her focus is now to “educate Gov. Chris Christie about the merits of this life-saving legislation.”

Christie’s office gave no indication of whether the governor would sign the bill. A spokesman said the governor’s office has a long-standing policy of not commenting on legislation until it has an opportunity to review a final bill.